Ignition coils are in heavy use for igniting internal combustion engines. In such ignition coils used for internal combustion engines, a primary electric wire is wound about a primary spool to form a primary coil, while a secondary electric wire is wound about a secondary spool to form a secondary coil. Further, the primary coil and the secondary coil are concentrically arranged in a casing to form a coil section. An end of the coil section is fitted to a fitting hole of a connector case section in which an igniter is arranged.
After winding the primary electric wire about the outer periphery of the primary spool, a winding end portion of the primary electric wire is fixed to a terminal provided at the primary spool. Then, the terminal provided at the primary spool and a terminal (conductor pin) provided at the connector case section are bonded together by performing a processing, such as resistance welding or fusing.
On the other hand, for example, in an ignition coil disclosed in Patent Document 1, a winding-start side and a winding-end side of a primary coil are fixed to a winding holder portion provided at a flange portion of a primary spool. Then, a terminal is fitted and fixed to the winding holder portion provided at the flange portion to hold the winding on the winding-start side and the winding-end side. The terminal is directly arranged at a connector portion to omit an intermediate terminal that would be provided at the primary spool.